1. Field of the Invention
The present invention relates to shift lever control devices for use in wheeled motor vehicles of a type having an automatic transmission mounted therein, and more particularly to shift lever control devices of a type which has the shift lever slidably moved in a cranked guide slot.
2. Description of the Prior Art
Among the shift lever control devices for controlling automotive automatic transmissions, there is a type which has the shift lever slidably moved in a cranked guide slot. In the control devices of this type, the shift lever is compelled to travel in a zig-zag manner due to the structural nature of the cranked guide slot.
One of the conventional shift lever control devices of such type is disclosed in Japanese automotive magazine "MOTOR FAN" issued on Jan. 1, 1982.
In order to clarify the task of the present invention, the conventional device disclosed in the magazine will be described with reference to FIG. 8 of the accompanying drawings, which is a schematical and partial plan view of the conventional device, showing an essential section which is relevent to the present invention.
Designated by numeral 2 is a cranked guide slot in and along which a shift lever 1 is slidably moved for the shifting operation. As is shown, the guide slot 2 has a terminal end portion 2a bent perpendicularly. A generally J-shaped shift lever holding member 3 is pivotally connected at one end to a fixed member (not shown) through a pivot shaft 3a. The holding member 3 has at the other end portion a guide recess 4a which has a roundly depressed bottom 4b. As may be understood from the drawing, during the pivotal movement, the holding member 3 can assume a first given position wherein an enclosed space for the shift lever 1 is defined by the terminal bent end portion 2a of the cranked guide slot 2 and the guide recess 4a of the holding member 3.
A spring biased detent roller 5a is connected to a free end of the holding member 3, which is resiliently and selectively engageable with two spaced notches 5b and 5c formed in a fixed member (no numeral). The detent roller 5a and the two notches 5b and 5c thus constitute a so-called "check mechanism" 5 for the holding member 3.
As is seen from the drawing, in a case wherein the holding member 3 assumes the above-mentioned first given position, the detent roller 5a is resiliently engaged with the notch 5b thereby holding the holding member 3 stationary.
When the shift lever 1 is manipulated to move from the terminal bent end portion 2a toward a major part of the guide slot 2, the holding member 3 is pivoted in a clockwise direction in the drawing to a second given position wherein the guide recess 4a is open to the major part of the guide slot 2 having the detent roller 5a resiliently engaged with the other notch 5c. Thus, thereafter, the shift lever 1 is movable in the major part of the guide slot 2 toward the other terminal end thereof.
When thereafter the shift lever 1 in the major part of the guide slot 2 is moved toward the entrance of the terminal bent end portion 2a, the shift lever 1 enters the guide recess 4a of the holding member 3 which has been kept in the second given position. When the shift lever 1 is then shifted into the terminal bent end portion 2a, the holding member 3 is returned to the first given position providing the operator (viz., driver) with a detent feeling.
However, due to its inherent construction, the shift lever control device described hereinabove has the following drawbacks.
First, when the shift lever 1 assumes the first given position as shown in FIG. 8, there is inevitably produced, between the shift lever 1 and one peripheral side (denoted by reference "c") of the terminal bent end portion 2a, a gap which may cause an undesirable play of the shift lever 1. In fact, at the first given position, only the diametrically opposed two portions "a" and "b" of the shift lever 1 are held or pressed by a terminal edge of the bent end portion 2a and one side edge of the guide recess 4a respectively.
Second, because of the nature of the check mechanism 5 employed in the device, there is produced a click metallic noise each time the detent roller 5a falls into the notch 5c or 5b.